Beta-naphthyl alkylidene carbazic acid esters

ABSTRACT

The preparation of substituted Beta -naphthyl alkylidene carbazic acid alkyl esters having antirhinoviral activity and method of use are described.

[lie States Patent [191 [Dusza et a].

[ BETA-NAPHTHYL ALKYLIDENE CARBAZIIC ACID ESTERS [73] Assignee: American Cyanamid Company,

Stamford, Conn.

[22] Filed: Dec. 17, 1973 [21] Appl, No.: 425,420

[52] US. Cl. 260/471 C, 424/300 [51] Int. Cl. C07c 125/06 [58] [Field of Search 260/471 C [4 1 Dec.24,197 i- [56] References Cited UNITED STATES PATENTS 3,560,503 2/1971 Anand ct ul. 260/47] Primary ExaminerL0rraine Av Weinberger Assistanl ExaminerL. A. Thaxton Attorney, Agent, or FirmErnest Y. Miller [57] ABSTRACT The preparation of substituted B-naphthyl aikylidene carbazic acid alkyl esters having antirhinoviral activity and method of use are described.

5 Claims, N0 Drawings thylidenel-carbazic 'naphthyl)ethylidenel-carbazic acid methyl ester, 3-(2- BIETA-NAPHTI'IYL ALKYLIDENE CARBAZIC ACID ESTERS DESCRIPTION OF THE INVENTION grown in plastic tissue culture dishes were infected with one of the viruses causing respiratory illness such as the common cold. These viruses include members of the picornavirus group including the rhinoviruses, for ex- 5 ample, types 18, 2, 5, 14 or 23 and including the en- This invention is concerned with novel substituted teroviruses, for example, Coxsackie A-l5 or A-2l. B-naphthyl alkylidene carbazic acid alkyl esters and Protection ofthe tissues to the cytopathic effects ofthe method of using the same. viruses was ascertained by means of a plaque inhibition In particular, this invention relates to compounds of test in which the test compound was adsorbed onto a the formula; filter paper disc and placed on the a ar used to overlay the infected cell monolayers, or by incorporation into HNHCOOR2 the said agar overlay. The agar overlay medium used I C for this purpose was of the following formulation:

I Minimum Essential Medium (Eagles) containing l5 Earles Salts (Grand Island Biological Company, Grand Island, N.Y.) and to which has been added: wherein R is selected from the group consisting of hydrogen and lower alkyl (C -C and R is lower alkyl l' 6)- I Ionagar No. 2 0.4%

The compounds of the present invention may be prea: w fi gl g-gz parfecll1 by methods which can be graphically illustrated fir f e (v/v) as o ows:

- E The virus-infected cell monolayers plus test com- C pound were incubated for 3 to 5 'days in a humidified atmosphere of 5 percent carbon dioxide at either 33 H2N NH COOR2 or 37C., depending on the virus. The ability of these R compounds to protect tissues from destruction by the H' 2 viruses was then evident after staining the residual, H Hcl) C uninfected, cells with 0.5 percent crystal violet in 20 1 percent ethanol.

1 A summar of the results obtained m the areas tested Ethanol y Reflux 1-2 hours t IS shown in the following Table.

TABLE I Rhinovirus Compound 1B 2 5 I4 23 3-[ I-(Z-Naphth l)ethylidene]-carbazic 'lCId ethyl ester '3-l l-t2Naphthyl)ethy|ideneI-carbazic acid methyl ester 3-il2iNuphthylmethylcne)-carbazic acid ct y ester H l-(2-Naphthyl)ethy|idenel-carbazic acid tort-butyl ester 'l- Protests tissue from destruction by virus wherein R and R are as defined above. Among the specific compounds which can be prepared by the above method are, for example: 3-[l-(2-naphthyl)eacid ethyl ester, 3-[1-(2- naphthylmethylene)-carbazic acid ethyl ester, 3-[ l-(2- naphthyl)ethylidene]-carbazic acid tertiary butyl ester, 3[ l-(2-naphthyl)ethylidene]carbazic acid pentyl ester, 3-[l-(2-naphthyl)propylidene1-carbazic acid butyl ester.

The compounds of the present invention exhibit antiviral activity against a variety of rhinoviruses. The following method is used to determine the anti-rhinoviral activity of the compounds. Confluent monolayers of a continuous cellline such as HeLa, HEp-Z, KB or L-l 32 In addition 3-[1-(2-naphthyl)ethylidene]-carbazic acid ethyl ester is also active in providing protection against Coxsackie A-l 3 and A-2l viruses and poliomyelitis type 2 and 3 viruses.

- which serves to resist disintegration in the stomach and permits the inner component to pass intact into the duodenum or to be delayed in release. A variety of mate- I rials can be used for such enteric layers or coatings,

such materials including a number of polymeric acids or mixtures of polymeric acids with such materials as shellac, shellac and cetyl alcohol, cellulose acetone and the like. A particularly advantageous enteric coating comprises a styrene-maleic acid copolymer together with known materials contributing to the enteric prop erties of the coating.

The liquid forms in which the novel compositions of the present invention may be incorporated for administration include suitably flavored emulsions with edible oils, such as, cottonseed oil, sesame oil, coconut oil, peanut oil, and the like, as well' as elixirs and similar pharmaceutical vehicles. Sterile suspensions or solutions can be prepared for parenteral use. lsotonic preparations containing suitable preservatives are also desirable for injection use.

The term dosage form as described herein refers to physically discrete units suitable as unitary dosage for warmblooded animal subjects, each unit containing a predetermined quantity of active component calculated to produce the desired therapeutic effect in association with the required pharmaceutical diluent, carrier or vehicle. The specification for the novel dosage forms of this invention are indicated by characteristics of the active component and the particular therapeutic effect to be achieved or the limitations inherent in the art of compounding such as active component for therapeutic use in warm-blooded animals as disclosed in this specification. Examples of suitable oral dosage forms in accord with this invention are tablets, capsules, pills, powder packets, granules, wafers, cachets, teaspoonfuls, dropperfuls, ampules, vials, segregated multiples of any of the foregoing and other forms as herein described.

DETAILED DESCRIPTION The following examples describe in detail the preparation of representative compounds of this invention.

EXAMPLE 1 Preparation of 3-[1-(2-Naphthyl)ethylidene]- carbazic acid ethyl ester A mixture of 5.0 gm. of 2-acetonaphthone, 3.12 gm. of ethyl carbazate and 2 drops of concentrated hydrochloric acid in 100 ml. of 95 percent ethanol is refluxed for 1.5 hours and then cooled to room temperature. The precipitate which forms is collected by filtration, dissolved in methylene chloride and passed through an acid silicate of magnesium column. The refluxing effluent is treated with hexane to crystallization. The product is collected and dried yielding 2.16 gm., melting point 133.5134.5C. Anal. Calcd. for C H N O C, 70.29; H, 6.29; N, 10.93. Found: C, 70.14; H, 6.25; N, 10.91.

EXAMPLE 2 Preparation of 3-[ l-(2-Naphthyl)ethylidene]- carbazic acid methyl ester A mixture of 8.5 gm. of 2-acetonaphthone and 4.5 gm. of methyl carbazate in 25 ml. of absolute ethanol containing 2 drops of concentrated hydrochloric acid is refluxed for 1.5 hours and then cooled. The precipitate is washed with hexane and then water, dissolved in methylene chloride and passed through an acid silicate of magnesium column. The refluxing effluent is treated with hexane to crystallization. The product is collected and dried, yielding 9.6 gm., melting point 130.513l.5C. Anal. Calcd. for C H N O C, 69.40; H, 5.83; N, 11.56. Found: C, 69.24; H, 5.80; N, 11.45.

EXAMPLE 3 Preparation of 3-(2-Naphthylmethylene)-carbazic acid ethyl ester A mixture of 15 gm. of B-naphthaldehyde and 10.4 gm. of ethyl carbazate in ml. of absolute ethanol containing 2 drops of concentrated hydrochloricacid is heated on a steam bath for 0.75 hours, cooled and then filtered. The precipitate is washed with ethanol and then water. The precipitate is dissolved in methylene chloride and passed through an acid silicate of magnesium column. The refluxing effluent is treated with hexane to crystallization. The product is collected by filtration, washed with hexane and dried yielding 12.0 gm., melting point 136.5137.5C. Anal. Calcd. for C H N O :C, 69.40; H, 5.83; N, 11.56. Found: C, 69.26; H, 6.04; N, 11.58.

EXAMPLE 4 Preparation of 3-[1-(2-Naphthyl)ethy|idene]- carbazic acid tertbutyl ester A, mixture of 8.5 gm. of 2-acetonaphthone and 6.6 gm. of tert-butyl carbazate in a solution of 94 m1. of absolute ethanol and 6 ml. of glacial acetic acid is heated on a steam bath for 2 hours and then cooled. The precipitate is collected, dissolved in methylene chloride and passed through an acid silicate of magnesium column. The refluxing effluent is treated with hexane to crystallization. The product is collected, washed with hexane and dried yielding 8.2 gm., melting point l78180C. Anal. Calcd. for C H N O C, 71.80; H, 7.09; N, 9.85. Found: C, 72.21; H, 7.38; N, 9.99.

We claim:

1. A compound of the formula:

(2-naphthyl)ethylidene]-carbazic acid tert-butyl ester. l k k 

1. A COMPOUND OF THE FORMULA:
 2. The compound in accordance with claim 1; 3-(1-(2-naphthyl)ethylidene)-carbazic acid ethyl ester.
 3. The compound in accordance with claim 1: 3-(1-(2-naphthyl)ethylidene)-carbazic acid methyl ester.
 4. The compound in accordance with claim 1: 3-(2-naphthylmethylene)-carbazic acid ethyl ester.
 5. The compound in accordance with claim 1: 3-(1-(2-naphthyl)ethylidene)-carbazic acid tert-butyl ester. 